CN1206036A - Process for fluid catalytic cracking of heavy feeds - Google Patents

Abstract

A process for the fluid catalytic cracking of heavy feeds under a heat balance regime, where at least one catalyst cooler external to the regenerators cools a stream of regenerated catalyst. A portion of said stream returns to the regenerators and a portion of the cooled regenerated catalyst is admixed to the non-cooled regenerated catalyst at a temperature substantially lower than the regenerator temperature, said admixture being brought into contact with the hydrocarbon feed to be cracked. As a result, the control of the catalyst circulation is rendered independent from the heat balance of the unit, with minimization of the thermal cracking, and therefore lower coke and fuel gas products.

Description

The method of fluid catalytic cracking of heavy feeds

The present invention relates to a kind ofly get involved thermal equilibrium and the method for improved fluid catalytic cracking.More particularly, the present invention relates to a kind of like this fluidized catalytic cracking method, wherein the change of cracking unit thermal equilibrium ultimate principle makes and improves by product productive rate equilibrated, mainly product productive rate equilibrated improves under heavy feed stock catalytic cracking situation, might improve the throughput of this method.This intervention is that riser tube is sent in two kinds of regenerator logistics, and wherein a kind of logistics is the regenerator logistics that is in regenerator temperature, and another logistics is through the logistics of refrigerative regenerator.

The catalyzer that fluid catalytic cracking or FCC form with fine particle materials in conversion zone by hydro carbons contacts and carries out.Different with hydrocracking, catalytic cracking is carried out under the condition that does not have added hydrogen or hydrogen consumption fully.Usually, the most common charging of sending into FCC technology is those refinery logistics that obtained by the vacuum distillation tower side stream, is called heavy vacuum gas oil; Perhaps, be called long residuum by the heavier refinery logistics of ratio vacuum gas oil that obtains at the bottom of the atmospheric tower; Perhaps both mixtures.These logistics that its typical density range is a 8-28 ° of API degree are sent in chemical process such as the catalytic cracking process, it is formed noticeable change takes place, so that change into the lighter hydrocarbon material flow of higher economic worth.

In the cracking reaction process, a large amount of coke as the by-product deposition of reaction on catalyzer.The high molecular weight material that coke is made of the hydro carbons that contains 4-8% (weight) hydrogen usually in it is formed.Usually the catalyzer that is called spent agent by brainstrust is removed from conversion zone continuously, used the catalyst make-up that is substantially free of coke that obtains from RS Regenerator Section simultaneously.In RS Regenerator Section, in the revivifier that keeps at high temperature, burn the coke that is deposited on the catalyst surface and in the hole.Remove coke by burning and make activity of such catalysts be recovered and discharge the heat of some amount, its quantity is enough to reach the heat demand of catalytic cracking reaction.The fluidisation of the catalyzer that obtains by gas stream makes the conveying (vice versa) of catalyzer between conversion zone and RS Regenerator Section become possibility.Catalyzer still is transported to heat the means of conversion zone from revivifier except it promotes this major function of katalysis of chemical reaction.

Conveying and the coke description of combustion method in revivifier between conversion zone and RS Regenerator Section of the cracking in the fluidizing catalyst stream of the relevant hydro carbons of prior art, catalyzer is a large amount of.Although the existing long history of FCC method, but still in the various technology of constantly seeking this method of improvement, so that improve the output of product such as gasoline and LPG that higher-value is arranged.Usually we can say that the main purpose of FCC method is the output maximum that makes these more valuable products.

Basically, available two kinds of methods make the output maximum of more valuable product.A kind of method is to improve so-called transformation efficiency, and it is corresponding to the output that reduces heavy product such as clarified oil and light cycle oil.Other method is to reduce the productive rate of coke and fuel gas, promptly reduces this method to generating these product selectivity.The result who reduces the output of coke and fuel gas increases the output of gasoline and LPG, and this just means that this method increases generating these valuable product selectivity.The other benefit is to use less air-blaster and rich gas compressor, and they are the machinery of large-scale high energy consumption, usually by the throughput scope of their decision FCC apparatus.

As you know, a key property of FCC method is that catalyzer contacts with the initial of charging, and it has most important influence to the transformation efficiency and the selectivity of the product of generation high value.In the FCC method, will inject position through the hydrocarbon feed of preheating near conversion zone or riser tube bottom, riser tube is the vertical pipe of a prolongation.Usually, the height of this pipe is a 20-40 rice, and diameter is a 0.5-1.5 rice.In riser tube, charging contact with the regenerator stream that has the some amount heat, and its heat is enough to that charging is atomized and the thermal load of main in the method thermo-negative reaction is provided.

After the riser tube of chemical reaction takes place, from reaction product, isolate in its surface and hole and deposit the spent agent of coke, and send into and be used for empyreumatic revivifier, so that recover activity of such catalysts and generation heat; When catalyst transport arrived riser tube, the heat of generation was used for this method.

Send into the product that the conditional decision of riser tube position generates in charging in reaction., obtain the initial mixture of regenerator and charging here, the most of components in the charging are heated to boiling point and vaporization.The total residence time of hydro carbons in riser tube only 2 seconds.In order to carry out catalytic cracking reaction, must in several milliseconds, make charging with the mixing section of catalyzer in vaporize so that can contact with granules of catalyst through the hydrocarbon molecules of vaporization.About 60 microns of the granularity of catalyzer, hydrocarbon molecules is passed the particulate hole, so that be subjected to the acid sites effect of catalyzer, finally causes catalytic cracking.Under the situation that can not reach rapid vaporization, the liquid distillate of charging carries out thermally splitting.

As you know, thermally splitting produces by product such as coke and fuel gas, especially when the resid feed cracking.Coke is except the inherent low value, and it goes back the duct of blocking catalyst.Therefore, do not wish that this point is the real-world objects of this method in riser tube bottom thermally splitting and catalytic cracking competition.

On the other hand, if charging is suitably atomized, so that form tiny spraying, just easier rapid vaporization of charging so on mutually at catalyzer.In order to obtain such spraying, developed various types and be used for injector charging injecting lift pipe.Evidence suggests that the temperature of charging in spraying gun is high more, the surface-area that feed spray is dripped is just big more, thereby the contact area between charging and the catalyzer is just big more, the difficulty or ease of remarkably influenced vaporization.Can prove that for the temperature range of resid feed of using and enforcement, owing to use higher feeding temperature, the increase of contact area can reach 30% in the FCC method.

In order to make the transformation efficiency maximum of charging, attempt usually in revivifier, from catalyzer, to remove coke to greatest extent.Can under the condition of partial combustion or perfect combustion, make the coke burning.

Under partial combustion, the gas that the coke burning produces is mainly by CO ₂, CO and H ₂O forms, and the coke content in regenerator is about 0.1 to 0.2% (weight).

Under perfect combustion, in the presence of a large amount of excess of oxygen, carry out, all CO that in fact generate in reaction change into CO ₂CO generates CO ₂Oxidizing reaction be strong heat release so that perfect combustion has bigger heat release, thereby produces very high regeneration temperature.But the catalyzer that perfect combustion obtains contains the coke that 0.07% (weight) is following, preferred 0.05% (weight) is following; Compare with partial combustion, except CO burning boiler, also have more benefit without high cost.

The increase of coke makes the coke of unit mass recycling catalyst increase under the combustion conditions in revivifier in spent agent.In traditional FCC apparatus, in combustion gases, from revivifier, remove with main heat in thermal regenerant stream.The increase of coke content increases the temperature of regenerator and the temperature difference between revivifier and the reactor on the spent agent.So thermal load and maintenance temperature of reaction for reactor is provided must reduce the flow velocity that regenerator is sent into reactor, promptly reduce so-called catalyst recirculation amount.But the temperature difference strengthens required lower catalyst circulation rate and makes catalystoil ratio decline between revivifier and the reactor, thereby transformation efficiency is descended.

Therefore, catalyzer is the function of the temperature that reaches in riser tube thermal load and the revivifier to the internal circulating load of reactor by revivifier, and the latter is the function of coke growing amount.Because the coke that generates in riser tube is subjected to the influence of catalyst recirculation amount itself, can draw, catalytic cracking process carries out under the thermal equilibrium scope; Based on above-described reason, under very high regeneration temperature, obtain undesirable operation.

Activity of such catalysts is not being had under the dysgenic condition, the temperature that the FCC catalyzer is allowed also has other restrictions.Usually, for the FCC catalyzer in modern times, the temperature of revivifier, thus the temperature of regenerator remain on below 760 ℃, preferred below 732 ℃ because surpass this temperature, the loss of catalyst activity is serious.The operating restraint of wishing is 685-710 ℃.Lower limit is mainly by guaranteeing that suitable coke incendiary need control.Device for the processing long residuum does not have the revivifier most applications of heat removal system to operate under 870-980 ℃ temperature range.

So, see and design factors that from the angle of catalyzer the cooling of revivifier is intended to make the temperature of revivifier to reach acceptable numerical value, so that reach industrial acceptable catalyst recirculation weight range from relating to.

This method is used to the FCC apparatus of the mixture of the various heavy feed stocks of cracking such as normal pressure residual oil or it and heavy vacuum gas oil.When available charging is the resid feed of high coke output and when regeneration when carrying out under perfect combustion, the cooling of revivifier is inevitable.

In this field, perfect combustion is increasing in practice, because except some other advantage, it can obtain quite low coke content on catalyzer, is lower than 0.05% (weight), thereby transformation efficiency is improved.

The processing that should be appreciated that heavy feed stock increases day by day, and such charging tends to make the coke growing amount to increase, and operational requirement is installed catalyst cooler under perfect combustion, so that the temperature of revivifier is remained under the acceptable limit.Usually, catalyst cooler is from from heat extraction the catalyst stream of revivifier, so that the catalyzer that turns back to revivifier is cooled basically.

The cooling of catalyzer has become the purpose of many patents.Water cooler in internal regenerator is arranged, and its operation is undertaken by spiral coil cooling tube, and cooling fluid is in the coil pipe internal recycling, for example referring to US2819951.Catalyst cooler in the revivifier outside is also arranged.For example, US2970117 openly can control the flow velocity that returns of the cold catalyzer of sending into revivifier by the temperature of revivifier.

Another possibility of heat-obtaining is the catalyzer that riser tube is sent in cooling from revivifier.The riser tube of sending in charging partly is equipped with catalyst cooler like this, and the catalyst recirculation amount heat that increases and remove revivifier more fully consequently is to cause the revivifier cooling.

But, further improve the catalyst recirculation amount at needs, to cause under the higher situation of the transformation efficiency that generates valuable product, system incurs loss because of low excessively regeneration temperature, and such temperature makes the operation can not be satisfactory.In the resid feed cracking, improve internal circulating load and wish, because these chargings are to be difficult to the cracked charging.

Make regenerator temperature drop to unacceptable numerical value (because the influence of above-mentioned thermal equilibrium) in order to prevent because the catalyst recirculation amount improves, the temperature of delivering to the charging of riser tube can correspondingly improve.Under this condition, the thermal load of riser tube remains to similar condition in the past, and different is that catalyzer is colder, and charging is hotter.This condition can not obtain best catalyst recirculation amount, but the temperature difference between catalyst stream and the incoming flow obviously descends.

By higher initial temperature and better the charging atomizing might accomplish to make with charging in the heavy component easy degree that atomizes increase this relevant temperature impellent and descend, it has reduced in the mixing section of charging and catalyzer, produces the appearance of the heat cracking reaction of coke and fuel gas.These conditions favourings are in the catalyzed reaction approach of FCC method elementary object, and make thermally splitting reduce to minimum.

The cooling of catalyzer used water, but this technology has some shortcomings, as equipment such as riser tube, cyclonic separator, fractionation overhead condenser and sour water system excess load; The deposition of ammonium salt increases in separation column; Waste water quantity increases and makes the power loss increase that water vapor causes, because the water of vaporization is not having condensation again under the condition of heat recuperation.

In order to overcome shortcoming, can use catalyst cooler with the water cooling riser tube.Catalyzer from revivifier cools off in high pressure steam generator, and directly sends into riser tube from vapour generator.Therefore, obtain strong optimization by high pressure steam generation equipment.With injection water ratio, produce a large amount of water vapors and mean energy-conservation significantly.

US4396531 is open, in the renovation process of the FCC catalyzer that a coke pollutes, and a kind of outer water cooler that is used to cool off the regenerator stream of sending into riser tube.In this water cooler, thermal regenerant obtains relative cold catalyzer with the cooling fluid contact that is feedwater under the condition of heat exchange; Catalyzer keeps the dense fluidized bed in cooling section; In fluidized-bed, the fluidizing agent circulation.Propose to regulate the flow velocity of the catalyst stream of sending into cooling section, so that might optimize the combination of each variable, these variablees comprise the heat that will remove; The passivation target of pollution metal such as nickel and vanadium; The content of uncondensed gas, they bring riser tube into catalyzer.It is said, come control reaction temperature by the cold relatively regenerator stream of sending into conversion zone.

What should emphasize is the catalyzer of delivering to riser tube by cooling, and the purpose of US4396531 is to cool off revivifier by improving the catalyst recirculation amount.The major objective of this patent is not to deliver to the catalyzer of riser tube and correspondingly add hot feed by cooling to reduce thermally splitting, although partly reach these targets.Obviously, the disclosure of this patent corresponds to the many patents that relate to the water cooler that makes catalyzer return revivifier, many improvement of the fluid thermal properties that proposition relates in heat exchange.

When being intended to that revivifier is cooled to be fit to the required temperature of revivifier operation, the disclosure of US4396531 can not obtain to the required regenerator temperature of FCC apparatus thermal equilibrium discussed above and to the catalyst recirculation amount suitable and independently control.US4396531 does not think the suitable thermally equilibrated advantage that influences FCC apparatus.One clearly evidence be that the rate of catalyst flow that changes from the water cooler to the riser tube by the valve (21) that operates in the corresponding standpipe (5) carries out temperature of reaction is controlled.In US4396531, people do not find and can independently control the catalyst recirculation amount of delivering to riser tube, thus the corresponding method of control catalystoil ratio.

So, with regard to the thermal equilibrium in the FCC apparatus, have Several Parameters to satisfy simultaneously: the cooling revivifier makes its temperature remain on suitable numerical value, except making the internal circulating load of catalyzer, thereby catalystoil ratio is remained on outside the proper level, and the latter means and obtains required temperature of reaction.Therefore, US4396531 does not consider the degree of freedom that constitutes catalystoil ratio as an independent variable.This is because this patent is not related to the thermal equilibrium of dispensing device, does not also pay close attention to the independent temperature of the catalyzer that contacts with charging and the temperature of charging itself controlled.

US4234411 is open, in a FCC method, a kind ofly controls the method that two or more deliver to the regenerator logistics of riser tube.According to the method that is proposed, in riser tube, want the cracked charging to contact with the first part regenerator, the flow velocity of catalyzer is the function of temperature of the mixture of this catalyst stream and charging there; This mixture of charging and catalyzer contacts with the second section regenerator then, and the flow velocity of catalyzer is by final controlling reaction temperature.In this patent, although regenerator is sent into riser tube two positions, in these two positions, catalyzer is under the identical temperature.The flow velocity of catalyzer changes with temperature of reaction.This patent is not considered the thermal equilibrium of modifier by any way; It does not utilize through the refrigerative catalyzer with the contact segment of charging in existence and through the benefit of the existence of the charging of heating.In addition, do not obtain the temperature to revivifier, the temperature of charging and the independent control of catalystoil ratio owing to recognize the thermally equilibrated ultimate principle of device, this patent.

US4257875 is similar to US4234411, and it proposes to send into regenerator selecting more than of riser tube.In disclosed method, first logistics of cyclic regeneration agent is sent into such speed, and this speed is enough to make the temperature of the mixture of it and charging to be raised to more than 454 ℃, preferably to surpass 510 ℃, so that make most of distillable fractions atomizing in the charging.This patent proposes a table, and wherein the temperature of charging is identical with prior art and patent with catalystoil ratio, shows that the thermal equilibrium to device does not change.

US5451313 proposes a kind of FCC method, wherein the dispersion that circulates the severity that reduces method and improve charging with regenerator by spent agent with the contacting of catalyzer.With the combination of spent agent and regenerator, so as catalyst mixture with make before charging contacts between two catalyst streams approaching or reach thermal equilibrium.Be lower than the temperature of regenerator by the temperature of the generation of the mixture between spent agent and the regenerator.The heating that the temperature decline of proposition granules of catalyst and catalyst amounts increase promote charging together is more even and the dispersion of charging in catalyzer is better.

But, there are three main shortcomings, these shortcomings have seriously limited application and the benefit of US5451313.

As for first shortcoming, find that when spent agent was recycled to riser tube, the catalyst amt amount that contacts with charging increased.This just makes charging contact minimizing with the regenerator particulate, and regenerator is the effective catalyst that promotes catalytic cracking reaction.On the other hand, the spent agent of sedimentation of coke on particle being arranged is SA catalyzer.It has reduced the transformation efficiency of device.In addition, spent agent has higher coke selectivity, because the coke catalysis that known coke formation reaction is existed, thereby undesirable coke growing amount is increased.So, promote the use of the spent agent part of thermally splitting rather than catalytic cracking to make the transformation efficiency decline of this method and make the selectivity variation, thereby reduced the economy of this method.The US5451313 disclosed method may only be fit to light-weight or through the charging cracking of the extremely low coke growing amount of having of hydrogenation.Therefore, this method does not show the cracking of the heavy feed stock that is applicable to that continuous increase is used in the FCC method, and these heavy feedstocks are to be difficult to cracked, and high coke growing amount is arranged, and heavy feed stock obtains by the highly polluted catalyzer of metal.

Second shortcoming that restriction US5451313 uses relates to the spent agent that uses the systemic circulation flow velocity, needs catalyst mixture in the bottom of riser tube.It is a cyclical operation, causes the oversize of riser tube, cyclonic separator, stripping tower and standpipe.These equipment are main equipments, and they make FCC apparatus increase huge expense.In addition, owing to the result that the stripping tower size increases, need to increase the flow velocity of stripped vapor, so that the speed that in this equipment, obtains suiting.So process cost increases equally.

The 3rd shortcoming (not too important anything but shortcoming) of the technology of mentioning among the US5451313 discussed as above-mentioned other patents, relate to this fact, the thermally equilibrated aspect of the not mentioned relative assembly of this patent, because catalyzer actually with under the identical temperature of the mixture of riser tube end catalyzer and charging, be recycled to riser tube begin the place, so be recycled to riser tube by spent agent, the thermal equilibrium of unlikely changeable device.So in fact spent agent stream does not increase the heat of riser tube or not from the riser tube heat removal.In view of the constant heat-transmission equilibrated of this logistics fact, whenever the feeding temperature change, its result will cause the temperature variation of the flow velocity and/or the revivifier of the regenerator of delivering to riser tube.For example, if the temperature of charging increases, because the riser tube thermal load reduces, the internal circulating load that regenerator is delivered to riser tube will reduce.Even the temperature of revivifier keeps steady state value by catalyst cooler, above-mentioned situation also can occur.So US5451313 can not acquire benefit from improving feeding temperature and don't making through the internal circulating load of regenerated catalyzer descends.To be a kind of method that keeps the regenerator internal circulating load by catalyst cooler by getting involved thermal equilibrium.This temperature that will cause revivifier descends, and this has bad influence to regeneration.So the disclosure of US5451313 can not make feeding temperature, regenerator temperature and catalyst recirculation amount become independent parameter.

So, this patent documentation does not propose ultimate principle of the present invention, promptly be in the thermal regenerant stream of regenerator temperature and the combination of flowing through the refrigerative regenerator, such catalyst mixture contacts with wanting the cracked charging, and catalyst cooler is used for making the regenerator bed cooling and is used in regenerator cooling in the charging of riser tube cracking hydrocarbons.

The inventive combination that is in the regenerator stream of controlled differing temps obtains the mixture of the regenerator of such temperature, and this temperature is set arbitrarily by the operator of device.This characteristic makes the internal circulating load of independent control regenerator become possibility, and is irrelevant with feeding temperature, regenerator temperature and temperature of reaction, as discussed in more detail below.Thermally equilibrated interference effect to device will be introduced this technology in the revolution notion that influences independence between the thermally equilibrated primary variables of FCC method.

Therefore, provide the demand that in this specialty, exists by the method for describing among the application and require to a kind of like this heavy feed stock FCC method, this method is being operated under the thermal equilibrium scope He under the low expense, generates a large amount of valuable products and small amount of fuel gas and coke.

The present invention includes a kind of FCC method that is mainly used in cracking heavy feedstocks, just, the boiling point of the hydrocarbon feed of main quantity is higher than 570 ℃.The present invention makes the productive rate that reduces undesirable product such as coke and gas, and the productive rate that improves valuable product such as gasoline and lighter gold-plating branch simultaneously becomes possibility, thereby has improved the economy of this method.

Heavy feed stock of the present invention under the condition of fluid catalytic cracking and the method for fluid catalytic cracking under the condition of the hydrogen that does not add may further comprise the steps: a) in conversion zone, the heavy hydrocarbon charging contacts with the catalyst stream that two kinds of regenerator streams under different temperature form mixture, mixture contains the main regenerator stream and the refrigerative time regenerator stream of heat, catalyst mixture has reached the equilibrated temperature, so that because described charging catalytic cracking result, in vapour phase, generate hydro carbons, and in solid phase, generate the coke that is deposited on the catalyzer, thereby activity of such catalysts is descended; (b) with the suitable equipment that is installed in behind conversion zone or the riser tube, from the catalyst mix logistics, isolate through the cracked hydrocarbon stream; (c) isolated catalyzer is delivered to stripping stage, deliver to RS Regenerator Section then, make the coke burning that is deposited on the granules of catalyst, obtain the regenerator particle, its activity is higher than spent agent; Regenerator is in the much higher temperature of temperature than the catalyst mix logistics of being mentioned.(d) make a part of thermal regenerant by the catalyst cooler outside revivifier, so that obtain flowing through the refrigerative regenerator; (e) part is delivered to mixing section through the refrigerative regenerator, mixing section is in the conversion zone front, and another part returns revivifier through the refrigerative regenerator; (f) thermal regenerant of a part of step (c) is delivered to mixing section in the conversion zone front; (g) thermal regenerant of step (c) and the cold regenerator of step (d) are mixed in the mixing section of conversion zone front, thereby obtain being in the catalyst mixture of equilibrium temperature; (h) in the thermal equilibrium scope, the thermal regenerant stream of step (c) and the cold regenerator stream of step (d) are mixed in conversion zone with wanting the charging of cracked heavy hydrocarbon.

So method of the present invention comprises that heavy feedstocks or residual oil contact with the mixture of two kinds of catalyst streams, mixture is by forming with flowing from the relative colder inferior regenerator of catalyst cooler from the main regenerator stream of revivifier.

The flow velocity of main flow is controlled by following temperature: the temperature at riser tube top, or the temperature of removing the product pipeline of fractionation section, or the temperature of any point between the premises, or the temperature of stripping tower.

The unlatching that by operator this catalyst stream is transported to the valve in the pipeline of riser tube from the temperature of time stream of catalyst cooler is directly controlled, perhaps the thermal regenerant stream by delivering to riser tube and the temperature of cold regenerator stream mixture are controlled automatically, and perhaps the usefulness signal that will be directly proportional with the catalyst recirculation amount any equipment of delivering to described control valve is controlled.

The charging that is blended in of the main flow of regenerator and time stream is sent into the lifting area under control of front, district and is obtained the mixture of regenerator, and the temperature of regenerator mixture is more much lower than the temperature of the regenerator of directly discharging from revivifier.Because catalyst mix flows the result of this lower temperature, helps catalytic cracking reaction, make heat cracking reaction minimum again simultaneously.

So, the invention provides a kind of like this FCC method of cracking-residuum, compare with existing technological method, higher gasoline yield and lower coke and gas yield are arranged.

In addition, the invention provides a kind of like this FCC method, the catalyst stream that wherein single catalyst cooler cools off the beds of revivifier independently and is sent to riser tube.

In addition, a basic sides of the present invention provides a kind of thermal equilibrium to FCC apparatus revolutionary improved FCC method.This revolutionary improvement refers to that the present invention can make following operation become possibility: regeneration temperature is remained unchanged and be in ideal value, the internal circulating load of regenerator is remained unchanged and be under the condition of ideal value, can make the temperature change of charging.This back one characteristic is not seen in art methods.

Therefore, according to the present invention, no matter when feeding temperature is raised to the higher temperature of more wishing, just can be by controlling the flow velocity that is recycled to the catalyzer of revivifier from water cooler, the temperature of revivifier is remained on optimal values.Therefore, under temperature of reaction control, because temperature head is lower between catalyst stream and the charging, the thermocatalyst stream of discharging from revivifier is low.

In addition, implement to compare with the prior art of FCC method, the effect of the valve of the cold catalyst recirculation amount of the present invention by control being removed riser tube so that described internal circulating load is improved, thereby avoids the regenerator internal circulating load of riser tube to descend.

This method has two benefits: the flow restoration and the ⅱ that ⅰ) make regenerator) simultaneously in the bottom of riser tube, be significantly less than in temperature under the temperature of art methods and obtain the regenerator mixture.

The low internal circulating load of resulting low temperature and former regenerator adapts, and it provides the heat demand of riser tube.

Therefore, catalystoil ratio can independently be controlled through the refrigerative rate of catalyst flow by control.With identical method, optimal values independently be controlled and be remained on to the temperature of revivifier can by the catalyst recirculation amount of delivering to revivifier.

So the present invention makes following operation become possibility: make the temperature reduction of the regenerator stream that contacts with the charging of FCC apparatus and make the temperature of the hydrocarbon feed of delivering to riser tube bring up to optimum temps.In addition, this enforcement can be accomplished by suitable intervention thermal equilibrium, and don't the improvement of thermally equilibrated its dependent variable of damage effect device, as hereinafter with discussed in detail.

In addition, with the mode of patentability difference being arranged with other art methods, provided by the invention have great economic benefit to thermally equilibrated influence, and this benefit obtains by minimizing thermally splitting, increase catalytic cracking, and this benefit is to the heavy feed stock particularly suitable.

Control under the control of temperature of reaction though deliver to the flow velocity of the thermal regenerant of riser tube, that delivers to riser tube both can be by the operator to having controlled through the unlatching of the Trunk Line valve of refrigerative catalyzer or by acting on described valve catalyst recirculation quantitative change apparatus sensitive is controlled automatically through the flow velocity of refrigerative catalyzer.

For example, certain relation is arranged is that everybody is familiar with to the internal circulating load of pressure reduction between riser tube bottom and its outlet and catalyzer.So the internal circulating load of catalyzer can be controlled automatically by the equipment that is installed in the differential pressure pickup in the riser tube.The signal that transmitter produces can be carried with traditional method, as electrical method or Pneumatic method.When the signal of this equipment acts on the valve of the cold regenerant flow rate of control, can control this flow velocity automatically, remain unchanged to cause total catalyst recirculation amount, and be not subjected to the influence of device changes in thermal balance.

Internal circulating load shown in the present independently another benefit of obtaining of ultimate principle is the unlatching that the temperature of thermocatalyst stream by delivering to riser tube and cold catalyst stream mixture is controlled the cold catalyzer valve of riser tube.When the temperature regulation catalyst recirculation by the temperature difference between the mixture of catalyst stream of contact charging and charging itself, can obtain a kind of method of control catalyst internal circulating load.

Therefore, the present invention also provides a kind of like this FCC method, and wherein from catalyst cooler and deliver to riser tube, its temperature is significantly less than the flow velocity of a part of regenerator stream of regenerator main flow and can controls automatically, and irrelevant with its dependent variable of device, so just guaranteed the independent control of catalystoil ratio.Do not have in the FCC apparatus that is controlled at prior art like this, because in traditional FCC method, this variable is the function of device thermal equilibrium (thermal load of riser tube), because there is not such degree of freedom.

In brief, the invention provides a kind of so main processing but be not only heavy feedstocks or the FCC method of resid feed, wherein reduce the temperature of regenerator stream and arrive minimum, and make the temperature maximum of hydrocarbon feed stream, thereby make the difference minimum between two temperature in the riser tube bottom in the riser tube bottom.So following variable is remained unchanged and be in optimum value: regeneration temperature, temperature of reaction and catalyst recirculation amount, they are to guarantee that the FCC method has the basic variable of maximum economy, mainly are when the cracking-residuum charging.

At last, the invention provides a kind of like this FCC method, wherein deep variation takes place by the possibility that independent these variablees of control are provided in the complementary ultimate principle of the thermally equilibrated primary variables of FCC method, thereby optimize the optimization of these variablees and entire method, obtain tangible economic benefit.

Accompanying drawing 1 is the front view of FCC conversion system of the present invention, comprises corresponding web member between revivifier, reactor and this two portions, comprising heat exchange section.

Accompanying drawing 2 is the front view of the FCC conversion system of the present invention of similar Fig. 1, and wherein heat exchange section changes to some extent.

Accompanying drawing 3 is the front view of the FCC conversion system of the present invention of similar Fig. 1 and 2, and the 3rd frame mode of heat exchange section is described.

The present invention relates to a kind of fluidized catalytic cracking method of heavy feed stock.The present invention be more particularly directed to contain the charging of high boiling fraction, as above 570 ℃.

Usually, describe in this manual with the method that requires and comprise that hydrocarbon feed stream contacts with the bottom of regenerator stream at the conversion zone of the prolongation vertical pipe composition that is called riser tube; Under situation of the present invention, regenerator stream is the regenerator main flow and the inferior mixture that flows of relative colder regenerator of relatively heat.Contacting of mixture of charging and regenerator stream makes cracking hydrocarbon, coke as by-product deposition on catalyzer.The catalyzer that deposits coke on it is called spent agent by brainstrust.

Behind riser tube, through cracked hydrocarbon stream and catalyst separating.Constitute reaction product through the cracked hydro carbons, be admitted to the fractionation system.

Spent agent is sent to stripping tower so that reclaim reaction product, otherwise they will be entrained in the revivifier with spent agent.

Then spent agent is delivered to revivifier.In RS Regenerator Section, be deposited on the coke burning on the granules of catalyst, activity of such catalysts is recovered, obtain pyritous regenerator particle.Most of heat of granules of catalyst is used for riser tube, so that for heating and vaporization feeding provide thermal load, and provides thermal load for the catalytic cracking reaction that is mainly thermo-negative reaction.

In view of the present invention relates generally to the cracking of heavy feedstocks, the perfect combustion scope is preferred for revivifier.Make like this owing to resid feed cracked result, a large amount of sedimentation of coke are regenerated better at last spent agent and are become possibility.Better regeneration guarantees that catalyzer has high reactivity, and this is very important for the cracking that is difficult to the cracked resid feed.As a result, the transformation efficiency of this method improves.

Water cooler outside revivifier makes a part of regenerator cooling.A part is returned revivifier through the refrigerative regenerator, and it mixes with beds in revivifier, to guarantee that suitable regeneration temperature value is arranged under balance.

Another part is delivered to riser tube through the refrigerative regenerator, and it mixes with direct regenerator stream from the much higher temperature of being in of revivifier there.Two catalyst streams constitute and the regenerator mixture of wanting the cracked raw material to contact.The temperature of the regenerator that passes through from the water cooler bypass than with riser tube the regenerator that effectively contact of charging flow the temperature height of mixture.In the present invention, heat exchanger not only plays traditional regenerator bed refrigerative effect that makes, but also plays the catalyzer that a cooling part is delivered to riser tube.This is because under the perfect combustion scope, is necessary to make revivifier CO burning in the sufficient to guarantee bed to generate CO ₂Temperature under operate, promptly preferably above 690 ℃.Under 690-705 ℃, wish to cool off and send to the catalyzer that contacts with charging from revivifier, make the temperature of the temperature of catalyzer near charging.Therefore, such temperature difference can drop to from about 500 ℃ and resemble 300 ℃ low, and this is extremely favourable for undesirable thermally splitting effect is reduced.

It is generally acknowledged that the single equipment refrigeration cycle is very favourable to the catalyst stream of revivifier and the catalyst stream of delivering to riser tube, this back one catalyst stream mixes with the regenerator that is in the regenerator bed temperature in riser tube.But the method for the present invention also equipment that separates that is used for separately cooling off two catalyst streams of available general use is carried out.

Be used for the known catalysts that heavy hydrocarbon cracked catalyzer can comprise any FCC of being generally used for practice.Preferred catalyzer is various zeolites, because they have high intrinsic activity and show high anti-deactivation to high-temperature steam with to metal.Usually, zeolite is dispersed in the porous inorganic carrier, as silicon oxide, aluminum oxide or zirconium white.Zeolite content in the catalyzer can reach 30% (weight) or higher.

Although the present invention can be used for belonging to the raw material of heavy vacuum gas oil cut scope, i.e. 380～560 ℃ raw material, it is specially adapted to resid feed or heavy feedstocks, and wherein the boiling range of 50% (weight) or more component is greater than 510 ℃.When cracking, such resid feed has high sedimentation of coke amount on catalyzer.Metal that exists in the charging and coke make catalyst deactivation by the active centre of blocking catalyst.

By catalyst regeneration, can remove coke from catalyzer and reach required degree, so that eliminate its inactivation influence.

But metal is accumulated on the catalyzer, and it is poisoned, in the inner fusion of catalyzer, so that the permanent active centre of stopping up.In addition, metal also promotes undesirable cracking reaction, so that disturbs required reaction process.Therefore, the existence of metal exerts an influence to operation, catalyst selectivity, the catalyst activity of revivifier and the quantity of the required live catalyst of activity that remains unchanged usually.Pollution metal comprises nickel, iron and vanadium.Usually, such metal pair selectivity has detrimentally affect, generates still less gasoline and more coke.

The embodiment that illustrates in 1 flow process with reference to the accompanying drawings, FCC method of the present invention comprises reactor 1, revivifier 5, catalyst cooler 19 and the conversion zone or the riser tube 12 of the prolongation of conversion zone is provided.Carrying out catalyst recirculation by following description contacts with charging with catalyzer.

For example, prolong a pipeline 6 from revivifier 5, it makes the regenerator of heat lead to the bottom 8 of riser tube 12, and prolongs a pipeline 18 from revivifier 5, and it makes the regenerator of heat lead to water cooler 19.Prolong a pipeline 20 from water cooler 19, it links to each other with the pipeline 24 that control valve 25 is housed, and a part is delivered to the bottom 8 of riser tube 12 through the refrigerative regenerator.Pipeline 20 also links to each other with pipeline 21, links to each other with pipeline 23 by control valve 22 again, and a part is delivered to revivifier through the refrigerative regenerator, so that make the bed cooling of revivifier.

The lifting of sending into by pipeline 10 contacts with the catalyzer at 8 places, bottom of riser tube 12 with fluidizing agent, so that catalyzer is remained in the fluidized state.Preferably dispersing apparatus porous ring of being familiar with by brainstrust or porous plate distribute the lift gas of the bottom 8 by riser tube 12.The mixture of hot catalyst stream and colder catalyst stream appears at half eminence 9 of riser tube 12.The ratio of the mixture of regenerator and feed stream 11 (it contacts with catalyzer in the first part of riser tube 12) is preferably 4-15, more preferably 6-9 in the part 9 of riser tube 12.

The temperature of the regenerator logistics that obtains in view of the mixture by logistics 6 and 24 is lower than the uncolled regenerator of prior art, the higher temperature of temperature during raw material can be implemented than common art methods is introduced riser tube 12, so that compare raw material with common practice and can vaporize rapidly, and mode is vaporized more uniformly.

In the embodiment of this specification sheets, material temperature of the prior art is 240 ℃, brings up to 360 ℃ of the present invention.Mathematical simulation shows, this raising of the material temperature that is made of long residuum means that the contact area between the feed spray that catalyzer and atomizing raw materials device produce increases more than 30%.The temperature difference between catalyzer and the charging also is significantly less than art methods, and this is another positive effect, has avoided the local superheating of raw material.These two effects combine and make undesirable thermally splitting reduce to minimum.

The temperature of the regenerator of heat is much higher than the cold relatively regenerator that leaves water cooler.The regenerator that leaves pipeline 6 is in 650-760 ℃, preferred 680-732 ℃ usually.

The cold regenerator of discharging from water cooler 19 is in 450-670 ℃, preferred 480-520 ℃ usually.

The thermal regenerant that contacts with hydrocarbon raw material in riser tube is 10: 1 to 2: 1, preferred 6: 1 to 4: 1 with the ratio of cold regenerator.

The temperature that the mixture of thermocatalyst stream and cold catalyst stream obtains in riser tube is 630-670 ℃, preferred 640-660 ℃.

The residence time of granules of catalyst in riser tube change between second at 0.3-8, preferred 1-5 second.

Riser tube is made of part 8,9 and 12.Part 12 is a hydrocarbon raw material cracked conversion zone.Conversion zone is a pneumatic transport from the thermal regenerant stream of revivifier with from the vertical pipeline of the mixture of the cold regenerator stream of catalyst cooler.Raw material uses the nozzle that is installed in the logistics 11 to send into the beginning part of riser tube part 12 usually, for simplicity, does not describe nozzle here.With before catalyzer contacts, the temperature of charging is 100-450 ℃, preferred 240-360 ℃.

In riser tube 12 ends monitoring temperature of reaction, be generally 510-570 ℃, preferred 520-560 ℃.This monitoring is undertaken by the temperature measuring equipment 70 that everybody is familiar with, and it links to each other with signal transmission apparatus 72 with monitor 71, and the latter affacts on the control valve 7.Therefore, for each the required temperature value that is used for monitor 71, such desirable value all compares with observed value.Therefore, monitor is opened valve 7, thereby makes the change in flow of the hot revivifier of delivering to riser tube.Unlatching for each valve 7 through revising, it can change catalystoil ratio, compares with art methods, and method of the present invention can make the unlatching of valve 25 change, so that will send into riser tube through the cold regenerator stream that changes, thereby former catalystoil ratio is changed.

Discharge from the end of riser tube by the mixture that the hydrocarbon vapours of spent agent and cracking reaction generation is formed through reaction, and the catalyst separating equipment by forming by parts 13,14 and 15.The diagram representative of such separating device refers to cyclonic separator; But any separator all can be used for removing spent agent from hydrocarbon product stream.Hydrocarbon stream is delivered to the fractionation part then through pipeline 16 and 28, in order to reclaim the useful products of catalytic cracking unit.

Sedimentation of coke flows to container 1 in the bottom of last granules of catalyst (spent agent) by equipment 13 and 15, reaches the extension of container 1 therefrom, and it is a stripping tower 2, and adverse current is removed the hydro carbons that is adsorbed on the catalyst surface there.The catalyst stream that is substantially free of hydrocarbon vapours leaves the stripping part by pipeline 3.The flow velocity of catalyzer is controlled by valve 4, and the latter's unlatching is controlled with the charge level of stripping tower.

Deliver to revivifier 5 through steam stripped spent agent through pipeline 3, so that form fluidized-bed layer, occur the desired burning that is deposited on the lip-deep coke of granules of catalyst there.Burning is by contacting and carry out with oxygen (normally air), and oxygen enters revivifier 5 by the import (logistics 17) of regenerator bottoms.Usually the cyclonic separator (not shown in order to simplify) that is installed in internal regenerator is removed the granules of catalyst that combustion gases are carried secretly, and combustion gases made catalyzer return catalizer bed in the past at pneumatic outlet.Coke burning on the granules of catalyst makes catalyzer and combustion gases heating.

Catalyst cooler is an equipment outside revivifier, by with this method normally beyond the fluid thermal exchange, from regenerator, remove heat.In the present invention, catalyst cooler 19 links to each other with revivifier 5 by pipeline 18; Pipeline 18 will be delivered to catalyst cooler 19 from the thermocatalyst stream of revivifier 5.Catalyst cooler can be any prior art equipment that is used for fluidized solids and other fluid thermal exchange.Usually, cold fluid is oiler feed, and it is represented with logistics 26 in Fig. 1, produces steam 27 there.

According to the preferred embodiments of the invention shown in Figure 1, catalyst cooler 19 plays two effects: not only make regenerator stream 21 coolings of returning revivifier 5, and make regenerator stream 24 coolings of delivering to riser tube, it will make the heavier hydrocarbon feeds cracking.The control of two logistics flow velocitys is independently carried out.

Therefore, the present invention is applicable to residual oil raw material cracked method ultimate principle except that comprising the thermal regenerant stream 6 from revivifier 5 of delivering to riser tube, also comprise cold regenerator stream 21 that returns revivifier 5 and the cold regenerator stream 24 of delivering to riser tube, so that logistics 24 and logistics 6 form mixture, it is the catalyst stream by riser tube part 9, is the mixture that effectively contacts with raw material.

Part 9 sufficiently longs of riser tube reach thermal equilibrium so that guarantee between two catalyst streams 24 and 6.Part 9 has long, the preferred 7-10 rice of 5-15 rice.In order to ensure mixing fully and rapidly between the two regenerators stream, in part 9, a kind of mixed stream 29 is injected, this fluid is water, steam or any other fluid, as fuel gas.Fluid injects by many nozzles of radially installing, with the cylindrical wall formation 30-60 degree angle of part 9, preferred 40-50 degree angle.According to the size of device, these nozzles have 2-12, preferred 4-8, and they are installed in the beginning of part 9, and just sending into the position from logistics 6 has very short distance.The rate of discharge of mixed stream by described nozzle is adjusted in this numerical value, and sufficient to guarantee has suitable mixing energy.The flow rate regulation of logistics 29 is arrived this numerical value, and sufficient to guarantee catalyzer slug flow under moderate density passes through part 9.The velocity ratio of the lift gas of the part 8 of this back one flow velocity and injecting lift pipe is 80: 20 to 60: 40.Confluce between part 9 and 12, promptly feedstream 11 is sent into the place, and caliber enlarges, and for simplicity, this expansion is not shown in the drawings.

According to the present invention, can control with the temperature at riser tube top from the flow velocity of the Primary Catalysts of revivifier 5 stream 6, such logistics 6 is in higher relatively temperature; And control from the temperature of the available in the same manner logistics 9 of flow velocity of the inferior catalyst stream 24 of catalyst cooler 19, logistics 24 is in relatively low temperature.The logistics that logistics 9 obtains for the mixture by thermal regenerant stream and cold regenerator stream.In this case, the temperature measuring equipment 50 of the prior art of connection operating device 51 is sent to control valve 25 with the signal of equipment 52 by signalling key 53.

In another embodiment, the flow velocity of logistics 24 is for example by controlling the pressure reduction apparatus sensitive in the riser tube.In this case, what be connected to prior art operating device 62 sends a pressure difference signal at the beginning of riser tube part 12 and terminal prior art pressure instrumentataion 60 and 61 by equipment 63 respectively, to equipment 52, arrives valve 25 by signalling key 53 then.

Signalling key 53 is a kind of prior art equipment that is used for instrumental technique, and it makes selects required operation control mode to become possibility.

According to the 3rd embodiment, the flow velocity of logistics 24 can be controlled according to the required direct Open valve of catalyzer global cycle amount by operator.But the flow velocity of logistics 24 also can be controlled by other any flow rate control methods, controls because one of main characteristic of the present invention is such the independent of logistics flow velocity, thereby guarantees independently controlling of catalyst recirculation amount.

Therefore, because the temperature that the mixture of two catalyst streams 24 and 6 reaches is lower than the temperature from the logistics 6 of revivifier 5, the material temperature of delivering to riser tube can improve.Therefore, the summation of two effects, i.e. the raising of catalyst stream decrease of temperature and feeding temperature helps reducing thermally splitting, reduces the productive rate of fuel gas and coke conversely, thereby gasoline is increased.

In another preferred embodiment of the present invention shown in Figure 2, a catalyst cooler can be used for the catalyst stream that riser tube is delivered in cooling separately, and another catalyst cooler refrigeration cycle is returned the catalyst stream of revivifier.Therefore, according to described Fig. 2, with regenerator stream 18 ' deliver to catalyst cooler 19 ', its uses and is generally the cold fluid of oiler feed as heat-eliminating medium.Through refrigerative catalyst stream 20 ' through valve 22 ', by pipeline 23 ' turn back to revivifier 5 ', make regenerator vessel under temperature control.With revivifier 5 ' logistics 30 deliver to another catalyst cooler 35, make transfer of heat give cold fluid 32, thereby produce high pressure steam 33 as oiler feed.What so obtain delivers to riser tube through refrigerative regenerator stream 31, flows 6 with the regenerator of part 8 ' rising by riser tube there ' mix.Catalyst mixture by part 9 ' rising and mixed stream 29 ' meet, then with hydrocarbon raw material 11 ' meet, and part 12 ' in 11 ' one react.Compare with first embodiment of the present invention, described second embodiment helps being provided at being different to return under the temperature of revivifier through the refrigerative catalyzer will deliver to the possibility of reaction riser tube through the refrigerative catalyzer, thereby improve the handiness of operation.

According to the 3rd embodiment preferred of the present invention shown in Figure 3, cool off the water cooler of the catalyst stream of delivering to riser tube separately and can accomplish this point by the heat exchange between the hydrocarbon raw material of catalyzer and cracking unit.In existing apparatus, this method can be avoided the raw materials furnace and heating of expansion instrument.Therefore, according to Fig. 3, regenerator logistics 18 " is delivered to catalyst cooler 19 ", it uses cold fluid 26 ", as oiler feed." return revivifier 5 " through the refrigerative catalyst stream by pipeline 23, make this container remain on temperature control down by similar mode shown in Figure 2.Regenerator stream 37 obtains being sent to riser tube 12 by catalyst cooler 42 " cooled catalyst stream 38.In the 3rd embodiment, heat-eliminating medium is a raw material itself, and the logistics of accepting from catalyst stream behind the heat 35 becomes logistics 36, when its injecting lift Guan Shiyu part 9 " catalyst mixture contact of rising by riser tube.

Now with following embodiment the present invention is described, these embodiment are not as limitation of the present invention.

Embodiment

Test is carried out in half-way unit, and lists the following table I in by simulation.These test comparison art methods and method of the present invention are to the catalytic cracking data of the residual oil raw material of different cracking complexities.The main characteristic of raw material is listed the table III in.

In the table I, corresponding to the option A row of explanation prior art, the temperature of beds is 690 ℃.Temperature of reaction is 560 ℃.Material temperature is 240 ℃.Catalystoil ratio as the function of draw three temperature is 7.9.Therefore, the temperature difference of regenerator temperature and material temperature is 450 ℃.240 ℃ material temperature is quite low to the cracking of the raw material that contains residual oil.This makes raw material more be difficult to rapid vaporization in riser tube, and fully contact is relevant between this vaporization and catalyzer and the raw material, and it does not occur in practice.As a result, the reaction that raw material carries out is mainly the thermally splitting mode, thereby coke and fuel gas are increased.

On the other hand, although the temperature of regenerator satisfies the regenerated requirement, be too high, so that occur thermally splitting once more for contacting with raw material.

Because it is not satisfied that the productive rate that obtains is listed the condition of the option A of table II in; According to option b, operator bring up to 290 ℃ with the temperature of raw material, and option b illustrates prior art equally.By improving from catalyst cooler and returning the flow velocity of the catalyst stream of revivifier, the temperature of revivifier remains on suitable value--and 690 ℃.The temperature difference between regenerator and the raw material drops to 400 ℃ from 450 ℃, so that thermally splitting reduces.But because the lower new surely thermal equilibrium of heat demand gauge of riser tube, the internal circulating load of catalyzer drops to 30.2 tons/minute from 36.8.Therefore, catalystoil ratio drops to 6.5 from 7.9.Because catalystoil ratio reduces even more importantly to the specific heat cracked that influences of overall yield, the productive rate of the main purpose product of this method--gasoline drops to 36.5% (weight) from 38%, and is listed as the table II, this means that economic benefit descends.

Get back to the listed condition row of scheme C in the table I now, it illustrates characteristic of the present invention.Can find out that material temperature brought up to 360 ℃.As mentioned above, by improving the flow velocity of regenerator, can keep 690 ℃ regenerator temperature.Deliver to the valve (as mentioned above can manually or automatically) of flow velocity of the refrigerative regenerator of riser tube by control, can under 500 ℃, the speed with 7.7 tons/minute carry catalyzer.In riser tube, this catalyzer mixes with the direct regenerator from revivifier that is in 690 ℃.The equilibrium temperature that the mixture that cold catalyst stream and thermocatalyst stream generate reaches is 647 ℃.Such equilibrium temperature has determined that total internal circulating load is 36.8 tons/minute, just in time as in the option A, so identical catalystoil ratio 7.9 is arranged.But the temperature difference between raw material and the catalyzer drops to 287 ℃ from 450, and thermally splitting significantly descends, and this also makes catalystoil ratio remain on optimum value 7.9 simultaneously.This performance is unknown in art methods.In addition, the temperature of charging is brought up to 360 ℃ from 240 ℃ and is also helped the thermally splitting minimizing, because increase by 30% through the charging of vaporization and the contact area of catalyzer; Because the operation of atomizing raw materials device is better.Therefore, table II listed productive rate shows that gasoline yield brings up to 39.7% (weight) (improving 4.5% (weight)) from 38.0% (weight), mainly is because the productive rate of fuel gas drops to 5.6% (weight) from 7.0.

For processing 7000 meters every day ³FCC apparatus, the added benefit that the present invention obtains is about 3,500,000 dollars/year (based on option As) or 5,300,000 dollars/year (based on option b).

Be to be understood that, the embodiment of following table I limits anything but, since opposite with prior art, in explanation the solution of the present invention C, any combination of catalyst recirculation amount all can be determined between two standpipes, replaces the catalystoil ratio of being determined by force by device thermal equilibrium so that guarantee required catalystoil ratio.Because identical reason, in scheme C, can select any other feeding temperature, and to catalystoil ratio without any detrimentally affect.In an embodiment, select 360 ℃, because for the raw material of present embodiment, 360 ℃ near the top temperatures that may occur thermally splitting in the charging process furnace.

The table I

Logistics	Parameter	Prior art option A option b	The present invention program C
				??28 ??11 ??6 ??24 ??9 ??- ??6 ??24 ??9 ??-	Temperature of reaction, ℃ feeding temperature, ℃ regeneration temperature, ℃ through the refrigerative catalyst temperature, ℃ catalyst mixture temperature, ℃ catalyst charge temperature difference, ℃ thermocatalyst internal circulating load, ton/minute cold catalyst recirculation amount, ton/minute global cycle amount, ton/minute catalystoil ratio, weight by weight	??560????560 ??240????290 ??690????690 ??690????690 ??450????400 ??36.8???30.2 ??36.8???30.2 ??7.9????6.5	??560 ??360 ??690 ??500 ??647 ??287 ??29.1 ??7.7 ??36.8 ??7.9

The table II

Product	Prior art		The present invention program C % (weight)
				Option A	Option b
	????H 2S fuel gas LPG gasoline light cycle oil clarified oil coke adds up to	????0.7 ????7.0 ????11.5 ????38.0 ????16.1 ????16.1 ????10.6 ????100.0				????0.7 ????6.4 ???11.5 ???36.5 ???17.0 ???17.9 ???10.0 ??100.0	????0.7 ????5.6 ???11.8 ???39.7 ???16.1 ???16.1 ???10.0 ???100.0

The table III

The logistics long residuum

Habitat of oil Cabiunas

Density, API degree 15.1

Density, 20/4 ℃ 0.9615

Conradson carbon residue, % (weight) 10.0

Sulphur, % (weight) 0.70

Basic nitrogen, ppm 1906

Nickel, ppm 21.1

Vanadium, ppm 22.4

Pitch prill, % (weight) 4.9

VABP，℃???????????????????528．5

Claims (27)

1. One kind under the fluid catalytic cracking condition, under condition without any added hydrogen, the method of heavy feedstocks fluid catalytic cracking, this method may further comprise the steps: a) in conversion zone or riser tube, the charging that contains heavy hydrocarbon is contacted with catalyst stream, wherein catalyst stream is the mixture of two kinds of regenerator streams, two kinds of catalyst stream have different temperature, the Primary Catalysts that such mixture contains the regenerator of heat flows and cold regenerator time catalyst stream, catalyst mixture has reached equilibrium temperature, described contact is such, so that is obtained the vapour phase hydro carbons and be deposited on making its active solid phase coke that descends on the catalyzer by the catalytic cracking of such charging; B) by being installed in the outer suitable equipment of conversion zone or riser tube, from described catalyst stream mixture, isolate through the cracked logistics; C) described separated catalyst stream is delivered to stripping stage, deliver to RS Regenerator Section then, the coke that is deposited on the granules of catalyst is burnt, than spent agent more highly active regenerator particle is arranged so that obtain; Regenerator is in the temperature more much higher than the temperature of described catalyst mixture.D) the regenerator stream of a part of heat that will be obtained by step c) is delivered to the catalyst cooler outside revivifier, flows through the refrigerative regenerator so that obtain; E) part that will be obtained by step d) is delivered to mixing section in conversion zone or riser tube front through the refrigerative regenerator, and another part is returned revivifier through refrigerative regenerator stream; (f) thermal regenerant of a part of step (c) is delivered to mixing section in the conversion zone front; (g) thermal regenerant of step (c) and the cold regenerator of step (d) are mixed in the mixing section of conversion zone front, thereby obtain being in the catalyst mixture of equilibrium temperature; H) the cold regenerator that the thermal regenerant that step c) obtained stream and step d) obtain flows and wants the cracked heavy feedstocks in conversion zone or riser tube, mix in the thermal equilibrium scope.
2. 2. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein heavier hydrocarbon feeds is that a kind of boiling range is that 380-560 ℃, API degree are the raw material of 8-28.
3. 3. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein catalystoil ratio is independently controlled by the flow velocity of cold catalyst stream.
4. 4. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein regenerator temperature is independently controlled to the internal circulating load of revivifier by cold catalyzer.
5. 5. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein the thermal regenerant stream of step c) is in 650-760 ℃.
6. 6. according to the method for the heavy feedstocks fluid catalytic cracking of claim 5, wherein the thermal regenerant of step c) stream preferably is in 680-732 ℃.
7. 7. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein the cold regenerator of step d) is in 450-670 ℃.
8. 8. according to the method for the heavy feedstocks fluid catalytic cracking of claim 7, wherein the cold regenerator of step d) preferably is in 480-520 ℃.
9. 9. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein step c) and d) the mixture of catalyzer in conversion zone or riser tube obtain the temperature of 630-670 ℃ of scope.
10. 10. according to the method for the heavy feedstocks fluid catalytic cracking of claim 9, wherein step c) and d) the mixing of catalyst stream in conversion zone or riser tube preferably obtain the temperature of 640-660 ℃ of scope.
11. 11. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein the residence time of granules of catalyst in conversion zone or riser tube changes between second at 0.3-8.
12. 12. according to the method for the heavy feedstocks fluid catalytic cracking of claim 11, wherein the residence time of granules of catalyst in conversion zone or riser tube preferably changes between second at 1-5.
13. 13. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein Re regenerator main flow and cold regenerator time stream are than being 10: 1 to 2: 1.
14. 14. according to the method for the heavy feedstocks fluid catalytic cracking of claim 13, wherein Re regenerator main flow and cold regenerator time stream are than being 6: 1 to 4: 1.
15. 15. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein Re regenerator main flow is delivered to the flow velocity Be Controlled of riser tube or conversion zone, so that guarantee independent control catalyst internal circulating load.
16. 16. according to the method for the heavy feedstocks fluid catalytic cracking of claim 15, wherein Re the regenerator main flow flow velocity of delivering to riser tube or conversion zone is controlled with riser tube or conversion zone top temperature.
17. 17. according to the method for the heavy feedstocks fluid catalytic cracking of claim 15, wherein Re the regenerator main flow flow velocity of delivering to riser tube or conversion zone is controlled by the temperature of hydro carbons separating device effluent.
18. 18. according to the method for the heavy feedstocks fluid catalytic cracking of claim 15, wherein Re the regenerator main flow flow velocity of delivering to riser tube or conversion zone is controlled by the stripping tower temperature.
19. 19., wherein control catalyst stream being transported to the ducted valve that carries out the blended mixing section between thermal regenerant stream and the cold regenerator stream from catalyst cooler by manually opened from the flow velocity of the cold regenerator time stream of catalyst cooler according to the method for the heavy feedstocks fluid catalytic cracking of claim 1.
20. 20. according to the method for the heavy feedstocks fluid catalytic cracking of claim 19, wherein regulate on the other hand can be by delivering to riser tube or conversion zone from the unlatching of the valve of the flow velocity of the cold regenerator time stream of catalyst cooler thermal regenerant stream and the temperature of the mixture that cold regenerator flows control automatically.
21. 21., wherein regulate from the unlatching of the valve of the flow velocity of the cold regenerator time stream of catalyst cooler and can control automatically by riser tube or conversion zone bottom and terminal pressure reduction on the other hand according to the method for the heavy feedstocks fluid catalytic cracking of claim 19.
22. 22., wherein can control with any flow rate control method, because the flow rate control of described logistics is independently from the flow velocity of the cold regenerator time stream of catalyst cooler according to the method for the heavy feedstocks fluid catalytic cracking of claim 1.
23. 23. method according to the heavy feedstocks fluid catalytic cracking of claim 1, wherein make charging can under 360 ℃ of such high temperature, enter conversion zone or riser tube becomes possibility for the regenerator stream of the mixture of the regenerator main flow of heat and cold regenerator time stream, so that charging is promptly vaporized, thereby vaporizes in uniform mode.
24. 24. according to the method for the heavy feedstocks fluid catalytic cracking of claim 23, although wherein can at high temperature operate, such method can be operated under 7.9 high like that catalystoil ratios equally.
25. 25. according to the method for the heavy feedstocks fluid catalytic cracking of claim 1, wherein in step a), it is a pipeline that described thermal regenerant stream and cold regenerator flow the mixing region, the diameter in described zone is less than the diameter of described conversion zone.
26. 26. according to the method for the heavy feedstocks fluid catalytic cracking of claim 25, catalyst stream homogenizing in the slug flow scope, under intermediate density, carry out in described mixing region wherein.
27. 27. according to the method for the heavy feedstocks fluid catalytic cracking of claim 26, the many nozzle injecting gas fluids such as the steam of installing by warp-wise in described mixing region that homogenizes of wherein said slug flow and logistics obtains.

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